Embodiments of the present invention relate to substrate processing chamber components that exhibit resistance to erosion.
In the processing of substrates, such as semiconductor wafers and displays, a substrate is placed in a process chamber and exposed to an energized gas to deposit or etch material on the substrate. During these processes, process residues are generated and deposited on internal surfaces in the chamber. For example, in chemical vapor deposition processes, deposition material can deposit on component surfaces in the chamber, such as on deposition rings and shadow rings. In subsequent process cycles, the deposited process residues “flake off” from the chamber component surfaces to fall upon and contaminate the substrate. Consequently, the deposited process residues are periodically cleaned from the chamber surfaces.
However, the exposed surfaces of the chamber components are often eroded during the cleaning processes or when exposed to other erosive gases. For example, during a dry-cleaning process, the components may be exposed to energized halogenated cleaning gases, such as NF3 or CF4, that can rapidly erode the component surfaces. The cleaning gases are typically activated by microwaves or RF energy. Other erosive gases, such as for example etching gases, can also undesirably erode the surfaces of the chamber components. Erosion of the chamber components is undesirable, as particles of the eroded component often flake off from the component and fall upon and contaminate the substrates being processed in the chamber.
In one version, the erosion resistance of the components is improved by providing components comprising an erosion-resistant ceramic material, such as for example, aluminum oxide. Ceramic materials such as aluminum oxide typically exhibit good resistance to erosion in energized gases, and can reduce the generation of particles in the chamber. For example, U.S. Pat. No. 6,083,451 to Gupta et al., describes an alumina ceramic material that is resistant to fluorine-containing plasma. However, even these materials do not provide sufficiently good results, as the ceramic materials can still become eroded by some gas formulations. When they do get eroded, the components can typically be cleaned and re-used in the chamber only a few times before they become too eroded for use and need to be replaced, a practice that can be both costly and result in downtime of the processing apparatus.
The chamber components can also be eroded by chemical solutions that are used to clean the components. Wet cleaning processes can use harsh cleaning chemicals, such as for example solutions comprising hydrofluoric acid, are sometimes used to clean process residues having compositions that are compositionally hard or otherwise difficult to clean. The surfaces of the chamber components are easily excessively eroded by such cleaning solutions, requiring the frequent replacement of the component.
Thus, there is a need for chamber components having improved resistance to erosion by energized gases, such as for example etching and cleaning gases, and cleaning solutions. There is a further need for such erosion resistant components to be made of ceramic materials, and methods of manufacturing such components.